Take a good look at who's at the lower right end of the racers line up. That's right, it's a freaking tamagotchi!!! I think this game really crossed a line somewhere that shouldn't have been crossed.
He was in the First Mario Kart Arcade GP, as well. And it's not like a Digimon would end up making the cut in Super Smash Bros. Brawl, like say... Agunimon/Burning Greymon/Aldamon!
Well, ever since Namco and Bandai became one, Bandai decided to add one of their Tamagotchi characters into the mix. If anything, they would've put in Agumon, Veemon, and Guilmon, or for that matter, Captain Gundam!
Just because Bandai not only made Tamagotchi but also Digimon doesn't mean we'll be seeing Pokemon mixed with Digimon. There's not even any hinting towards that.